If i understood your question correctly, here is my suggestion:

You can make use of option modifier 'i' - ignore case.

Also you go through perlre.

if($current_subject =~ /\b\Q$filter\E\b/i)

Prasad

In reply to Re: Checking for all cases of a word by prasadbabu
in thread Checking for all cases of a word by MonkPaul

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